Which kingdom consists of organisms that are unicellular and lack a nuclear membrane?

• A. Animalia
• B. Plantae
• C. Monera
• D. Fungi

Answer: (C)

The kingdom that consists of unicellular organisms lacking a nuclear membrane is Monera. Organisms in this kingdom are prokaryotic, meaning they do not have a defined nucleus or other membrane-bound organelles. This distinguishes them significantly from the other kingdoms listed.

Monera includes bacteria and archaea, both of which are single-celled organisms. Their genetic material is typically found in a region called the nucleoid, which is not surrounded by a membrane, unlike the eukaryotic cells found in the Animalia, Plantae, and Fungi kingdoms. In contrast:

• Animalia consists of multicellular organisms that have complex structures and possess a true nucleus.

• Plantae comprises multicellular organisms that can perform photosynthesis and also have a true nucleus.

• Fungi are primarily multicellular (with the exception of yeast, which is unicellular), and they possess a nucleus along with other membrane-bound organelles.

Understanding the characteristics of these kingdoms highlights why Monera is uniquely defined by its prokaryotic, unicellular nature.